Tiens j'avais zappé la fin du délire. Et Compte tu est un piètre détective!
Bon sinon j'ai déniché la réponse à ma question sur la vitesse d'images différentes sur entre la diffusion US/Euro. C'est sur la page wikipédia de Buffy:
"4% speed difference
The Region 2 and 4 DVDs play the episodes at 4% faster than the Region 1 DVDs. This reduces the running time of each episode by about two minutes (not counting the "scenes from previous episodes"). It also causes the sound to be raised by two-thirds of a semitone. For example, a C note is raised to a note two-thirds of the way from C to C♯.
The speeds of the different region DVDs match the speeds used during the original television broadcasts in the respective countries. Thus the Region 1 DVD plays the video at the same speed as the American broadcasts (which is the speed at which the show was taped), while the Region 2 and 4 DVDs plays the video at the slightly faster speed that was used during the original British broadcasts. This effect is not particular to the Buffy DVDs but affects all television shows, because film that uses 23.976 frames per second is sped up for PAL that uses 25 (in the NTSC standard it is telecined and there is no speed variation). But since the signal from a DVD player is ultimately analog, the Region 2 and 4 DVDs will still play at the faster speed when played on an American television with a multi-region DVD.
In Brazil the standard color system is not PAL, but PAL-M which is also 24 frames per second. In addition to that, all DVD releases, despite being Region 4 are in NTSC, so the frame rate is also 24 frames per second."
http://en.wikipedia.org/wiki/Buffy_the_Vampire_Slayer_DVDs#Widescreen
Je vous laisse lire et apprendre l'anglais pour ceux qui ont de la peine 